Some Insights on the Use of Polyols-Based Metal Alkoxides Powders as Precursors for Tailored Metal-Oxides Particles

In this paper, we describe the synthesis of tailormade cobalt and manganese oxides by a two-step preparation method. The first step consists of precipitating metal alkoxide powders from aliphatic polyalcohol solutions of salts. Their particle size, composition, and morphology can be independently tuned by controlling the precipitation conditions (type of alcohol and concentration). The second step involves thermal decomposition under air, leading to crystalline metal oxides, whose specific surface area and crystallite size can be adjusted by a careful selection of the alcohol used and the annealing temperature. More specifically, we found that the crystallite size of these oxides is determined by the amount of heat released during the combustion of the organic component. Since the size and morphology of the precursors are strictly maintained during the pyrolysis treatment, we can therefore achieve an accurate control of the different aspects of the texture of metal oxide powders. Preliminary results show that this approach can be successfully extended to bimetallic phases.